The Long-Term Evolution (LTE) is a long-term evolution technology. A Physical Downlink Control Channel (PDCCH) is composed of CCE and used for bearing Downlink Control Information (DCI). The CCE is divided into a public space CCE (hereafter referred to as a public CCE) and a private space CCE (hereafter referred to as a private CCE), wherein the public CCE comprises 16 CCEs from the 0th CCE to the 15th CCE, and the rest is the private CCE. The literature of the 3rd Generation Partnership Project (3GPP), TS36.213.8.7.0, stipulates that: for the DCI needing the public CCE, the CCE aggregation level L of 4 or 8 can only be used, wherein when the CCE aggregation level L is 4, the start position of the CCE is respectively at the 0th, the 4th, the 8th or the 12th CCE, and when the CCE aggregation level L is 8, the start position of the CCE is respectively at the 0th or the 8th CCE; and for the DCI needing the private CCE, the CCE occupied by and allocated to the DCI is determined by a Hash function which is related to subframe number, CCE sum, CCE aggregation level L, the number of PDCCH candidates M(L) and the Radio Network Temporary Identity (RNTI) of a User Equipment (UE). According to the literature of 3GPP TS36.212.8.7.0, the DCI comprises the DCI in the format 0, format 1, format 1A, format 1B, format 1C, format 1D, format 2, format 2A, format 3 and format 3A, wherein the DCI in the format 0 (hereafter referred to as DCI0) is used for the uplink authorization of a UE; and the DCI in the format 1, format 1A, format 1B, format 1C, format 1D, format 2 and format 2A (hereafter referred to as DCIx) is used for the downlink allocation of a UE.
Only the private CCE resource can be allocated to the DCI in the format 1, format 1B, format 1D, format 2 and format 2A; only the public CCE resource can be allocated to the DCI in the format 1C, format 3 and format 3A; and either the public CCE resource or private CCE resource may be allocated to the DCI in the format 0 and format 1A. The DCI in the format 1C, format 3, and format 3A is called the public DCI, which aims at all the UEs in a cell. The DCI of a single UE (comprising the DCI in the format 0, format 1, format 1A, format 1B, format 1D, format 2 and format 2A) is called the DCI of the UE (or the private DCI).
The Media Access Control (MAC) layer needs some ways for the allocation of the CCE resource.
At present, the technology about the allocation of the CCE resource comprises: judging the CCE aggregation level L used by the public DCI and the DCI of the UE according to the wideband Channel Quality Identity (CQI) and Reference Signal Receiving Power (RSRP) information reported by the UE, or determining the CCE aggregation level L used by the UE according to the quantity of DCIx and DCI0 to be scheduled and the CCE resource. These technologies have the following defects: for the allocation of the public CCE, how to allocate the idle CCE resource in the public CCE is not clear; and for the allocation of the private CCE, how to allocate the idle CCE resource in the number of PDCCH candidates M(L) is not clear. In addition, the DCI in the same format contains different bits in different cell downlink bandwidths, and the DCI in the same format contains fewer bits in the smaller cell downlink bandwidth, and vice versa.